Problem: Tiffany eats at a restaurant and the cost of her meal is $\$37.00$. She would like to leave a $15\%$ tip. What is her total bill including tip?
Solution: The tip amount is equal to $15\% \times \$37.00$ We can find the tip by first calculating a $10\%$ tip and a $5\%$ tip, and then adding those two numbers together. To calculate a $10\%$ tip, move the decimal point in $\$37.00$ one place to the left. $10\%$ $\times \$37.00$ $\$3.70$ To calculate a $5\%$ tip, divide the $10\%$ tip amount in half. $5\%$ $\times \$37.00 = $ $\$3.70$ $ \div 2 = $ $\$1.85$ Adding the two amounts together gives us $\$3.70$ $\$1.85 =$ $ \$5.55$ The cost of the meal plus the amount of the tip will equal the total bill amount. $\$37.00 + \$5.55 = $ $\$42.55$ The total cost of the bill is $\$42.55$.